Feeding of zeolite A to poultry

ABSTRACT

A method of improving the quality of egg shells of laying poultry or laying hens without deleterious effects on the contents of the poultry egg shells by adding a small amount of zeolite A to the feed of the poultry.

BACKGROUND OF THE INVENTION

The present invention is in the general field of poultry farming andrelates particularly to the feeding of laying fowl or layers.

The demand for poultry eggs, especially chicken eggs has expandedconsiderably over the last decade. The poultry industry has grown from ahome industry to a large scale manufacturing industry in which tens ofthousand of eggs are produced daily at single farms or egg layinginstallations. Some eggs are produced for eating and some eggs areproduced for hatching. One problem with such large scale egg producingis breakage. Even a slight crack in an egg makes it unsuitable forhatching and most other marketing purposes. It is estimated that somesix percent of all eggs produced are lost for marketing because ofcracking or breakage. Shell strength is very important to inhibitbreakage. The stronger the egg shell, the less likely the egg will becracked or broken. Machinery and techniques necessary for carefullyhandling the eggs to avoid breakage are expensive and time consuming.

It is therefore an important object of the present invention to providea means for increasing the strength of the shell of a poultry eggwithout increasing production costs and without having any deleteriouseffect on the food value or quality of the egg itself.

Another substantial loss of egg production estimated to be about a sevenpercent loss is the production of shell-less eggs. Any reduction inshell-less eggs can be an important factor in large scale eggproduction.

An article by C. Y. Chung et al from Nongsa Sihom Youngu Pogo 1978, 20(Livestock) pp. 77-83 discusses the effects of cation exchange capacityand particle size of zeolites on the growth, feed efficiency and feedmaterials utilizability of broilers or broiling size chickens.Supplementing the feed of the broilers with naturally occurringzeolites, such as clinoptilolite, some increase in body weight gain wasdetermined. Chung et al also reported tha earlier results at theLivestock Experiment Station (1974, 1975, 1976--Suweon, Korea) showedthat no significent difference was observed when 1.5, 3, and 4.5 percentzeolite was added to chicken layer diets.

U.S. Pat. No. 3,836,676 issued to Chukei Komakine in 1974 discloses theuse of zeolites as an adsorbent for adhesion moisture of ferrous sulfatecrystals in an odorless chicken feed comprising such crystals andchicken droppings. The results were said to be no less than those in thecase where chickens were raised with ordinary feed.

Experiments have been in progress in Japan since 1965 on the use ofnatural zeolite minerals as dietary supplements for poultry, swine andcattle. Significant increases in body weight per unit of feed consumedand in the general health of the animals was reported (Minato, Hideo,Koatsugasu 5:536, 1968). Reductions in malodor were also noted.

Using clinoptilolite and mordenite from northern Japan, Onagi, T. (Rept.Yamagata Stock Raising Inst. 7, 1966) found that Leghorn chickensrequired less food and water and gained as much weight in a two-weektrial as birds receiving a control diet. No adverse effects on health ormortality were noted. The foregoing Japanese experiments were reportedby F. A. Mumpton and P. H. Fishman in the Journal of Animal Science,Vol. 45, No. 5 (1977) pp. 1188-1203.

Canadian Pat. No. 939,186 issued to White et al in 1974 discloses theuse of zeolites having exchangeable cations as a feed component in thefeeding of urea or biuret non-protein (NPR) compounds to ruminants, suchas cattle, sheep and goats. Natural and synthetic as well as crystallineand non-crystalline zeolites are disclosed. Zeolites tested includednatural zeolites, chabazite and clinoptilolite and synthetic zeolites X,Y, F, J, M, Z, and A. Zeolite F was by far the most outstanding andzeolite A was substantially ineffective.

In a recent study at the University of Georgia, both broilers and layerswere fed small amounts (about 2%) of clinoptilolite, a naturallyoccurring zeolite from Tilden, Tex. The egg shells from the hensreceiving zeolite were slightly more flexible as measured bydeformation, slightly less strong as measured by Instron breakingstrength, and had a slightly lower specific gravity. The differences inegg shell quality were very small. This type of zeolite was ineffectivein producing a stronger egg shell. An article written by Larry West andJohn Shutze entitled "The Influence of Feeding Zeolites to Poultry UnderField Conditions" summarizing the studies was presented atZeo-Agriculture '82.

A study by H. S. Nakaue of feeding White Leghorn layers clinoptilolite,reported in 1981 Poultry Science 60:944-949, disclosed no significantdifferences in egg shell strength between hens receiving the zeolite andhens not receiving the zeolite.

Zeolites are crystalline, hydrated aluminosilicates of alkali andalkaline earth cations, having infinite, three-dimensional structures.

Zeolites consist basically of a three-dimensional framework of SiO₄ andAlO₄ tetrahedra. The tetrahedra are cross-linked by the sharing ofoxygen atoms so that the ratio of oxygen atoms to the total of thealuminum and silicon atoms is equal to two or O/(Al+Si)=2. Theelectrovalence of each tetrahedra containing aluminum is balanced by theinclusion in the crystal of a cation, for example, a sodium ion. Thisbalance may be expressed by the formula Al/Na=1. The spaces between thetetrahedra are occupied by water molecules prior to dehydration.

Zeolite A may be distinguished from other zeolites and silicates on thebasis of their composition and X-ray powder diffraction patterns andcertain physical characteristics. The X-ray patterns for these zeolitesare described below. The composition and density are among thecharacteristics which have been found to be important in identifyingthese zeolites.

The basic formula for all crystalline sodium zeolites may be representedas follows:

    Na.sub.2 O.Al.sub.2 O.sub.3.xSiO.sub.2.yH.sub.2 O.

In general, a particular crystalline zeolite will have values for "x"and "y" that fall in a definite range. The value "x" for a particularzeolite will vary somewhat since the aluminum atoms and the siliconatoms occupy essentially equivalent positions in the lattice. Minorvariations in the relative number of these atoms do not significantlyalter the crystal structure or physical properties of the zeolite. Forzeolite A, the "x" value normally falls within the range 1.85±0.5.

The value for "y" is not necessarily an invariant for all samples ofzeolites. This is true because various exchangeable ions are ofdifferent size, and, since there is no major change in the crystallattice dimensions upon ion exchange, the space available in the poresof the zeolite to accommodate water molecules varies.

The average value for "y" for zeolite A is 5.1. The formula for zeoliteA may be written as follows:

    1.0±0.2Na.sub.2 O.Al.sub.2 O.sub.3.1.85±0.5SiO.sub.2.yH.sub.2 O.

In the formula, "y" may be any value up to 6.

An ideal zeolite A has the following formula:

    (NaAlSiO.sub.4).sub.12.27H.sub.2 O

Among the ways of identifying zeolites and distinguishing them fromother zeolites and other crystalline substances, the X-ray powderdiffraction pattern has been found to be a useful tool. In obtaining theX-ray powder diffraction patterns, standard techniques are employed. Theradiation is the Kα doublet of copper and a Geiger counter spectrometerwith a strip chart pen recorder is used. The peak heights, I, and thepositions as a function of 2θ where θ is the Bragg angle, are read froma spectrometer chart. From these, the relative intensities, 100 I/I_(o),where I_(o) is the intensity of the strongest line or peak and d theinterplanar spacing in angstroms corresponding to the recorded lines arecalculated.

X-ray powder diffraction data for a sodium zeolite A are given in TableI.

                  TABLE I                                                         ______________________________________                                        X-RAY DIFFRACTION PATTERN FOR ZEOLITE A                                                                 100 I                                               h.sup.2 + k.sup.2 + 1.sup.2                                                                     d(Å)                                                                              I.sub.o                                             ______________________________________                                         1                12.29   100                                                  2                8.71    70                                                   3                7.11    35                                                   4                6.15    2                                                    5                5.51    25                                                   6                5.03    2                                                    8                4.36    6                                                    9                4.107   35                                                  10                3.895   2                                                   11                3.714   50                                                  13                3.417   16                                                  14                3.293   45                                                  16                3.078   2                                                   17                2.987   55                                                  18                2.904   10                                                  20                2.754   12                                                  21                2.688   4                                                   22                2.626   20                                                  24                2.515   6                                                   25                2.464   4                                                   26                2.414   >1                                                  27                2.371   3                                                   29                2.289   1                                                   30                2.249   3                                                   32                2.177   7                                                   33                2.144   10                                                  34                2.113   3                                                   35                2.083   4                                                   36                2.053   9                                                   41                1.924   7                                                   42                1.901   4                                                   44                2.858   2                                                   45                1.837   3                                                   49                1.759   2                                                   50                1.743   13                                                  53                1.692   6                                                   54                1.676   2                                                   55                1.661   2                                                   57                1.632   4                                                   59                1.604   6                                                   ______________________________________                                    

The more significant d values for zeolite A are given in Table II.

                  TABLE II                                                        ______________________________________                                        MOST SIGNIFICANT d VALUES FOR ZEOLITE A                                       d Value of Reflection in Å                                                ______________________________________                                        12.2 ± 0.2                                                                 8.7 ± 0.2                                                                  7.10 ± 0.15                                                                5.50 ± 0.10                                                                4.10 ± 0.10                                                                3.70 ± 0.07                                                                3.40 ± 0.06                                                                3.29 ± 0.05                                                                2.98 ± 0.05                                                                2.62 ± 0.05                                                                ______________________________________                                    

Occasionally, additional lines not belonging to the pattern for thezeolite appear in a pattern along with the X-ray lines characteristic ofthat zeolite. This is an indication that one or more additionalcrystalline materials are mixed with the zeolite in the sample beingtested. Small changes in line positions may also occur under theseconditions. Such changes in no way hinder the identification of theX-ray patterns as belonging to the zeolite.

The particular X-ray technique and/or apparatus employed, the humidity,the temperature, the orientation of the powder crystals and othervariables, all of which are well known and understood to those skilledin the art of X-ray crystallography or diffraction can cause somevariations in the intensities and positions of the lines. These changes,even in those few instances where they become large, pose no problem tothe skilled X-ray crystallographer in establishing identities. Thus, theX-ray data given herein to identify the lattice for a zeolite, are notto exclude those materials which, due to some variable mentioned orotherwise known to those skilled in the art, fail to show all of thelines, or show a few extra ones that are permissible in the cubic systemof that zeolite, or show a slight shift in position of the lines, so asto give a slightly larger or smaller lattice parameter.

A simpler test described in "American Mineralogist," Vol. 28, page 545,1943, permits a quick check of the silicon to aluminum ratio of thezeolite. According to the description of the test, zeolite minerals witha three-dimensional network that contains aluminum and silicon atoms inan atomic ratio of Al/Si=2/3=0.67, or greater, produce a gel whentreated with hydrochloric acid. Zeolites having smaller aluminum tosilicon ratios disintegrate in the presence of hydrochloric acid andprecipitate silica. These tests were developed with natural zeolites andmay vary slightly when applied to synthetic types.

U.S. Pat. No. 2,882,243 describes a process for making zeolite Acomprising preparing a sodium-aluminum-silicate water mixture having anSiO₂ :Al₂ O₃ mole ratio of from 0.5:1 to 1.5:1, and Na₂ O/SiO₂ moleratio of from 0.8:1 to 3:1, and an H₂ O/Na₂ O mole ratio of from 35:1 to200:1, maintaining the mixture at a temperature of from 20° C. to 175°C. until zeolite A is formed, and separating the zeolite A from themother liquor.

It is an important object of the present invention to provide animproved feed formulation for laying poultry or layers which contains asmall amount of zeolite A.

It is a principal object of the invention to provide a poultry feedcontaining zeolite A which improves the quality of the shell of apoultry egg without causing a deleterious effect on the egg itself.

Another object of the invention is to provide an improved process forincreasing the strength of egg shells from laying poultry wherein aneffective amount of zeolite A is added to the diet of the poultry.

Still another object of the invention is to cost effectively increasepoultry egg production.

Yet a further object of the present invention is to decrease theproduction of shell-less eggs by laying poultry.

Other objects and advantages of the invention will be more fullyunderstood from a reading of the description and claims hereinafter.

SUMMARY OF THE INVENTION

The present invention relates to a method of improving the quality,i.e., the strength of egg shells of layers or laying poultry withoutdeleterious effects on the contents of the egg itself wherein a smallamount of zeolite A is added to the feed of the layers, and to a poultryfeed composition containing zeolite A.

DESCRIPTION OF THE PREFERRED EMBODIMENT

It has been discovered that the addition of a relatively small amount ofzeolite A to a regular or standard feed for laying chickens or henseffectively improves the quality of the egg shell with no significantchanges in egg production, egg weight or feed consumption. Zeolite A ispreferably added in amounts of from about 0.25 percent to about 4.00percent of weight of the total feed.

A typical feed preparation for large scale laying hen operationscomprises the following by weight percent:

    ______________________________________                                        Corn               62-68                                                      Soy Bean Meal      18-24                                                      Limestone          5-9                                                        Alfalfa Meal       1                                                          Phosphates         2                                                          Sand               1-2                                                        Vitamins, Amino Acids                                                                            0-1                                                        Salt and Other Minerals                                                       ______________________________________                                    

Zeolite A is added to such feed formulation in small amounts by weightpercent of up to about four. Greater amounts may be used, but maydeprive the layers of the desired amount of nutrients. Greater amountsare also likely to be cost ineffective. A preferred amount of zeolite Ais from about one-half to about two percent by weight of the total feedformulation. A most preferred amount of zeolite A is about 0.75 to about1.50 weight percent of the total feed formulation.

The most convenient means of measuring egg shell strength is bymeasuring the specific gravity of the egg. This is simply done byimmersing the egg in solutions of salt water of varying strengths. It iswell known in the art that specific gravity correlates with egg shellstrength. As specific gravity of the egg is raised, the strength of theegg shell is increased.

Using Ethyl EZA® zeolite, a commercially available sodium zeolite A, anumber of tests were conducted to determine the effect of zeolite on eggshell quality.

EXAMPLE I

Procedure: 480 hens (Dekalb XL pullets) were divided into eight equalgroups and fed one of the following dietary treatments for a minimum ofsix weeks:

    ______________________________________                                                      Calcium  Zeolite A                                              Diet          (wt. %)  (Wt. %)                                                ______________________________________                                        1             4.00     0                                                      2             4.00     0.75                                                   3             4.00     1.50                                                   4             4.00      0.68*                                                 5             2.75     0                                                      6             2.75     0.75                                                   7             2.75     1.50                                                   8             2.75      0.75**                                                ______________________________________                                         *diet not adjusted for calcium                                                **zeolite added on top except diet not adjusted for Cl                   

The diet fed to the hens consisted principally of corn supplemented witha soybean meal (SBM) and limestone. Smaller amounts of alfalfa meal,dicalcium phosphate (DiCalP), a synthetic amino acid (DL-methionine),salt, a commercial vitamin and mineral supplement for layers(Micro-Mix). Sand and/or hydrochloric acid (HCl) were added to somediets. Each diet assured that the hens received all of the requirednutrients and minerals.

Diets 1-4 contained 1,238 calories per pound, 16% protein, 0.55% totalsulfur amino acids, 4% calcium and 0.70% total phosphorous.

Diets 5-8 contained 1,292 calories per pound, 16% protein, 0.55% totalsulfur amino acids, 2.75% calcium and 0.70% phosphorous.

All diets were isocaloric and isonitrogenous within treatments and aredetailed in Table A.

                                      TABLE A                                     __________________________________________________________________________               Experimental Diets for Zeolite Study (Weight Percent)                         Diet No.                                                                      1   2    3    4      5   6    7    8                                          4.00% calcium        2.75% calcium                                 Ingredient 0.0 0.75 1.50 .68 (special)                                                                        0.0 0.75 1.50 0.75                            __________________________________________________________________________    Corn       63.80                                                                             63.80                                                                              63.80                                                                              63.80  67.83                                                                             67.83                                                                              67.83                                                                              67.83                           SBM        21.41                                                                             21.41                                                                              21.41                                                                              21.41  20.69                                                                             20.69                                                                              20.69                                                                              20.69                           Alfalfa meal                                                                             1.00                                                                              1.00 1.00 1.00   1.00                                                                              1.00 1.00 1.00                            Dicalcium Phosphate                                                                      2.07                                                                              2.07 2.07 2.07   2.03                                                                              2.03 2.03 2.03                            Limestone  9.14                                                                              9.14 9.14 9.14   5.87                                                                              5.87 5.87 5.87                            DL-methionine                                                                            0.01                                                                              0.01 0.01 0.01   --  --   --   --                              Salt       0.35                                                                              0.10 --   0.35   0.35                                                                              0.10 --   0.10                            Micro-mix  0.50                                                                              0.50 0.50 0.50   0.50                                                                              0.50 0.50 0.50                            Sand       1.72                                                                              0.82 --   1.04   1.72                                                                              0.82 --   1.23                            Zeolite A  --  0.75**                                                                             1.50**                                                                             0.68*  --  0.75**                                                                             1.50**                                                                             0.75**                          HCl        --  0.40 0.57 0.00   --  0.40 0.57 --                                         100.0                                                                             100.0                                                                              100.0                                                                              100.0  100.0                                                                             100.0                                                                              100.0                                                                              100.0                           __________________________________________________________________________     *0.68 is the special zeolite. (Diet 4)                                        **0.75 and 1.50 is zeolite A.                                            

Tests criteria were as follows:

1. Egg production (weekly)

2. Feed consumption (weekly)

3. Egg specific gravity (weekly)

4. Egg weight (weekly)

5. Shell weight (middle and end of experiment)

6. Serum calcium at termination

7. Body weight at initiation and termination

8. Mortality

All eggs laid during a 3-day period each week of the experiment and thefirst week prior to the experiment were used for specific gravity andegg weight measurements.

The results are summarized in Tables B, C, D, E, F and G as follows:

                                      TABLE B                                     __________________________________________________________________________    EGG SPECIFIC GRAVITY*                                                             No. of                                                Avg. for            Diet                                                                              Eggs  Week 0                                                                             Week 1                                                                              Week 2                                                                             Week 3                                                                              Week 4                                                                             Week 5                                                                              Week 6                                                                             Week 7                                                                             Week                                                                               8                   __________________________________________________________________________                                                              Weeks               1-4 240   80.24                                                                              80.33 80.70                                                                              81.03 80.90                                                                              80.52 78.21                                                                              80.76                                                                              80.69                                                                              80.39               5-8 240   80.04                                                                              78.69 78.32                                                                              79.15 78.57                                                                              77.75 76.48                                                                              78.99                                                                              78.80                                                                              78.34               1 and 5                                                                           120   79.88                                                                              78.37 77.63                                                                              78.16 77.96                                                                              77.14 75.42                                                                              77.90                                                                              77.74                                                                              77.54               2 and 6                                                                           120   79.64                                                                              79.13 79.47                                                                              79.93 79.83                                                                              79.43 77.20                                                                              80.10                                                                              79.51                                                                              79.33               3 and 7                                                                           120   80.56                                                                              80.60 81.14                                                                              81.59 80.84                                                                              79.87 78.85                                                                              80.67                                                                              81.15                                                                              80.59               4 and 8                                                                           120   80.47                                                                              79.93 79.79                                                                              80.67 80.33                                                                              80.08 77.91                                                                              80.83                                                                              80.58                                                                              80.01               1   60    80.27                                                                              80.12 79.42                                                                              80.30 79.86                                                                              79.49 77.59                                                                              79.53                                                                              79.19                                                                              79.44               2   60    79.70                                                                              79.03 80.53                                                                              81.17 81.27                                                                              80.67 78.86                                                                              81.01                                                                              81.29                                                                              80.48               3   60    80.35                                                                              81.84 81.96                                                                              81.92 81.66                                                                              81.53 79.16                                                                              81.33                                                                              81.91                                                                              81.44               4   60    80.64                                                                              80.33 80.88                                                                              80.73 80.82                                                                              80.38 77.22                                                                              81.18                                                                              80.38                                                                              80.24               5   60    79.50                                                                              76.63 75.83                                                                              76.03 76.06                                                                              74.80 73.25                                                                              76.28                                                                              76.30                                                                              75.65               6   60    79.60                                                                              79.24 78.41                                                                              78.70 78.39                                                                              78.20 75.55                                                                              79.19                                                                              77.73                                                                              78.17               7   60    80.77                                                                              79.35 80.32                                                                              81.26 80.01                                                                              78.21 78.54                                                                              80.01                                                                              80.40                                                                              79.76               8   60    80.31                                                                              79.54 78.70                                                                              80.61 79.83                                                                              79.79 78.60                                                                              80.47                                                                              80.77                                                                              79.79               __________________________________________________________________________     *Divide by 1000 and add 1 to convert to Actual Specific Gravity.         

                                      TABLE C                                     __________________________________________________________________________    EGG PRODUCTION (Percent Hen Per Day)                                              No. of                                                                        Percent                                               Avg. for            Diet                                                                              Calculations                                                                           Week 0                                                                             Week 1                                                                             Week 2                                                                             Week 3                                                                             Week 4                                                                             Week 5                                                                             Week 6                                                                             Week 7                                                                             Week                                                                               8                   __________________________________________________________________________                                                              Weeks               1-4 240      89.88                                                                              86.44                                                                              88.59                                                                              85.10                                                                              87.97                                                                              87.87                                                                              87.54                                                                              86.53                                                                              84.46                                                                              86.81               5-8 240      90.21                                                                              86.59                                                                              84.17                                                                              81.99                                                                              84.65                                                                              83.45                                                                              82.84                                                                              82.58                                                                              81.82                                                                              83.51               1 and 5                                                                           120      90.42                                                                              89.25                                                                              88.50                                                                              85.82                                                                              87.86                                                                              87.74                                                                              85.48                                                                              84.82                                                                              85.25                                                                              86.84               2 and 6                                                                           120      90.08                                                                              84.55                                                                              86.43                                                                              84.96                                                                              87.13                                                                              86.46                                                                              86.69                                                                              84.67                                                                              82.71                                                                              85.45               3 and 7                                                                           120      89.58                                                                              85.12                                                                              85.46                                                                              81.98                                                                              86.32                                                                              83.93                                                                              85.02                                                                              85.65                                                                              84.22                                                                              84.71               4 and 8                                                                           120      90.08                                                                              87.14                                                                              85.12                                                                              81.42                                                                              83.93                                                                              84.52                                                                              83.57                                                                              83.09                                                                              80.36                                                                              83.65               1   60       90.00                                                                              90.00                                                                              90.07                                                                              86.19                                                                              90.00                                                                              88.33                                                                              86.67                                                                              84.76                                                                              87.38                                                                              87.93               2   60       90.00                                                                              83.62                                                                              85.95                                                                              85.39                                                                              87.84                                                                              88.86                                                                              89.10                                                                              88.15                                                                              82.09                                                                              86.38               3   60       89.67                                                                              84.76                                                                              88.81                                                                              84.52                                                                              86.90                                                                              87.38                                                                              86.77                                                                              88.46                                                                              85.27                                                                              86.61               4   60       89.83                                                                              87.38                                                                              89.52                                                                              84.28                                                                              87.14                                                                              86.90                                                                              87.62                                                                              84.76                                                                              83.10                                                                              86.34               5   60       90.83                                                                              88.49                                                                              86.91                                                                              85.45                                                                              85.71                                                                              87.14                                                                              84.29                                                                              84.87                                                                              83.12                                                                              85.75               6   60       90.17                                                                              85.48                                                                              86.91                                                                              84.52                                                                              86.43                                                                              84.04                                                                              84.29                                                                              81.19                                                                              83.33                                                                              84.52               7   60       89.50                                                                              85.48                                                                              82.12                                                                              79.44                                                                              85.74                                                                              80.48                                                                              83.28                                                                              82.83                                                                              83.17                                                                              82.82               8   60       90.33                                                                              86.91                                                                              80.72                                                                              78.57                                                                              80.72                                                                              82.14                                                                              79.52                                                                              81.43                                                                              77.62                                                                              80.95               __________________________________________________________________________

                  TABLE D                                                         ______________________________________                                        SHELL WEIGHT (Grams/Egg)                                                               No. of                     Avg. for                                  Diet     Eggs    Week 4      Week 8 8 Weeks                                   ______________________________________                                        1-4      240     5.32        5.23   5.28                                      5-8      240     5.12        5.08   5.10                                      1 and 5  120     5.06        5.06   5.06                                      2 and 6  120     5.22        5.14   5.18                                      3 and 7  120     5.31        5.23   5.27                                      4 and 8  120     5.29        5.19   5.24                                      1        60      5.23        5.20   5.22                                      2        60      5.37        5.27   5.32                                      3        60      5.40        5.29   5.35                                      4        60      5.29        5.18   5.24                                      5        60      4.89        4.93   4.91                                      6        60      5.08        5.00   5.04                                      7        60      5.21        5.17   5.19                                      8        60      5.29        5.21   5.25                                      ______________________________________                                    

                                      TABLE E                                     __________________________________________________________________________    FEED CONSUMPTION (Grams Per Hen Per Day)                                          No. of                                        Avg. for                    Diet                                                                              Weighings                                                                           Week 1                                                                             Week 2                                                                             Week 3                                                                             Week 4                                                                             Week 5                                                                             Week 6                                                                             Week 7                                                                             Week 8                                                                             8 Weeks                     __________________________________________________________________________    1-4 240   105.48                                                                             108.16                                                                             109.76                                                                             110.13                                                                             112.85                                                                             105.64                                                                             110.57                                                                             115.53                                                                             109.76                      5-8 240   103.91                                                                             101.62                                                                             106.01                                                                              96.66                                                                             107.96                                                                             103.42                                                                             107.12                                                                             112.09                                                                             104.85                      1 and 5                                                                           120   112.06                                                                             105.92                                                                             109.32                                                                             107.44                                                                             112.54                                                                             106.08                                                                             110.57                                                                             116.80                                                                             110.09                      2 and 6                                                                           120   101.85                                                                             104.96                                                                             107.04                                                                             105.92                                                                             109.13                                                                             102.66                                                                             108.82                                                                             113.69                                                                             106.76                      3 and 7                                                                           120   102.08                                                                             105.07                                                                             107.99                                                                             101.47                                                                             110.17                                                                             105.25                                                                             109.16                                                                             112.40                                                                             106.70                      4 and 8                                                                           120   102.78                                                                             103.60                                                                             107.20                                                                              98.76                                                                             109.76                                                                             104.12                                                                             106.84                                                                             112.35                                                                             105.67                      1   60    113.25                                                                             109.55                                                                             112.98                                                                             115.07                                                                             117.42                                                                             106.76                                                                             113.94                                                                             119.90                                                                             113.61                      2   60     99.45                                                                             106.05                                                                             107.28                                                                             110.78                                                                             111.20                                                                             102.75                                                                             109.22                                                                             113.21                                                                             107.49                      3   60    104.65                                                                             109.60                                                                             111.13                                                                             108.85                                                                             111.98                                                                             107.66                                                                             110.73                                                                             115.78                                                                             110.05                      4   60    104.56                                                                             107.43                                                                             107.65                                                                             105.82                                                                             110.78                                                                             105.38                                                                             108.40                                                                             113.21                                                                             107.90                      5   60    110.86                                                                             102.30                                                                             105.65                                                                              99.81                                                                             107.65                                                                             105.41                                                                             107.21                                                                             113.69                                                                             106.57                      6   60    104.24                                                                             103.88                                                                             106.80                                                                             101.05                                                                             107.07                                                                             102.57                                                                             108.42                                                                             114.16                                                                             106.02                      7   60     99.52                                                                             100.53                                                                             104.85                                                                              94.08                                                                             108.37                                                                             102.83                                                                             107.59                                                                             109.03                                                                             103.35                      8   60    101.01                                                                              99.77                                                                             106.75                                                                              91.70                                                                             108.74                                                                             102.87                                                                             105.28                                                                             111.48                                                                             103.45                      __________________________________________________________________________

                  TABLE F                                                         ______________________________________                                        BODY WEIGHT (Grams per Hen)                                                           No. of                                                                Diet    Weighings      Week 0   Week 1                                        ______________________________________                                        1-4     240            1,538.58 1,550.63                                      5-8     240            1,518.58 1,520.00                                      1 and 5 120            1,526.25 1,565.00                                      2 and 6 120            1,528.00 1,542.00                                      3 and 7 120            1,515.58 1,492.00                                      4 and 8 120            1,544.50 1,542.25                                      1       60             1,541.67 1,579.33                                      2       60             1,525.83 1,543.17                                      3       60             1,518.67 1,507.00                                      4       60             1,508.17 1,573.00                                      5       60             1,510.83 1,550.67                                      6       60             1,530.17 1,540.83                                      7       60             1,512.50 1,477.00                                      8       60             1,520.83 1,511.50                                      ______________________________________                                    

                                      TABLE G                                     __________________________________________________________________________    EGG WEIGHTS (Grams per Egg)                                                       No. of                                                Avg. for            Diet                                                                              Weighings                                                                           Week 0                                                                              Week 1                                                                             Week 2                                                                             Week 3                                                                             Week 4                                                                              Week 5                                                                             Week 6                                                                             Week 7                                                                              Week                                                                               8                   __________________________________________________________________________                                                              Weeks               1-4 240   59.04 59.87                                                                              59.98                                                                              60.06                                                                              60.33 59.95                                                                              59.88                                                                              60.19 60.19                                                                              60.05               5-8 240   58.85 59.38                                                                              59.45                                                                              59.59                                                                              59.84 59.81                                                                              59.51                                                                              59.60 59.97                                                                              59.64               1 and 5                                                                           120   58.58 59.12                                                                              59.49                                                                              59.53                                                                              59.64 59.77                                                                              59.59                                                                              60.14 60.22                                                                              59.69               2 and 6                                                                           120   58.93 59.96                                                                              59.91                                                                              59.84                                                                              60.13 59.88                                                                              59.64                                                                              59.97 60.09                                                                              59.93               3 and 7                                                                           120   58.95 59.72                                                                              59.80                                                                              59.86                                                                              60.26 59.77                                                                              59.81                                                                              59.72 60.01                                                                              59.87               4 and 8                                                                           120   59.31 59.69                                                                              59.67                                                                              60.06                                                                              60.31 60.08                                                                              59.73                                                                              59.76 59.99                                                                              59.91               1   60    58.74 59.66                                                                              60.03                                                                              60.03                                                                              60.03 59.81                                                                              60.13                                                                              60.70 60.77                                                                              60.18               2   60    59.21 60.28                                                                              59.98                                                                              60.05                                                                              60.37 60.56                                                                              59.93                                                                              60.39 60.23                                                                              60.22               3   60    58.94 59.62                                                                              60.26                                                                              60.00                                                                              60.57 59.56                                                                              59.92                                                                              59.88 60.13                                                                              59.99               4   60    59.26 59.92                                                                              59.66                                                                              60.17                                                                              60.05 59.85                                                                              59.54                                                                              59.78 59.61                                                                              59.82               5   60    58.42 58.59                                                                              58.95                                                                              59.03                                                                              58.95 59.73                                                                              59.04                                                                              59.58 59.66                                                                              59.19               6   60    58.66 59.64                                                                              59.84                                                                              59.64                                                                              59.90 59.20                                                                              59.34                                                                              59.54 59.96                                                                              59.63               7   60    58.96 59.83                                                                              59.34                                                                              59.72                                                                              59.95 59.97                                                                              59.71                                                                              59.56 59.89                                                                              59.75               8   60    59.35 59.46                                                                              59.70                                                                              59.96                                                                              60.56 60.32                                                                              59.93                                                                              59.75 60.36                                                                              60.01               __________________________________________________________________________

A review of the test data in Table B shows that zeolite A provided adefinite benefit on shell quality, and had no significant effect on theother qualities studied except possibly for shell weight. Twoconcentrations (0.75%, 1.5%) were evaluated because of sodiumlimitations and for those levels, the data showed a linear relationshipwith concentration.

In Table C zeolite A had no significant effect on production (% henday). However there is some indication that a slight reduction occurred,particularly with Diet 8 in the 2.75% Ca series (i.e. low-Ca).

In Table D there appears to be an indication of some benefits fromzeolite A.

Previous indications that feed consumption was reduced without anyreduction in egg or body weight or in egg production could not besubstantiated by the statistical data. As shown in Table E 1.5% zeoliteA reduced feed consumption, relative to baseline, at both Ca levels inWeeks 1 and 4. However this did not occur in the other six weeks of thetrial. Thus if we look at the results for the 8th week:

    ______________________________________                                        % Ca       Run No.  Feed Cons. (g/hen/day)                                    ______________________________________                                        2.75       1        113.69                                                    2.75       2        114.16                                                    2.75       3        109.03                                                    2.75       4        111.48                                                    ______________________________________                                    

The reduced value is most likely attributable to a palatabilityconsideration. Laying hens usually eat more than they need. Any factor,such as feed dustiness, can reduce intake by up to 5% without an adverseeffect.

Tables F and G show no significant benefits for body and egg weights.

EXAMPLE II

Procedure: 480 hens were divided into eight equal groups and fed one ofthe following dietary treatments for a minimum of three months.

    ______________________________________                                                      TSAA     Zeolite A                                              Diet          (Wt. %)  (Wt. %)                                                ______________________________________                                         9            0.51     0                                                      10            0.51     0.75                                                   11            0.51     1.50                                                   12            0.51      0.68*                                                 13            0.61     0                                                      14            0.61     0.75                                                   15            0.61     1.50                                                   16            0.61      0.68*                                                 ______________________________________                                         *special zeolite  10.43% Ca and 0.52% Na.                                

All diets were isocaloric and isonitrogenous and are detailed in TableH.

Tests criteria were the same as in Example I.

The components of the diets were also similar as those of Example I.

Diets 9-12 contained 1237 calories per pound, 17% protein, 0.61% TSAA(Total Sulphur Amino Acids), 3.75% calcium and 0.70% phosphorus.

Diets 13-16 contained 1262 calories per pound, 14.78% protein, 0.51%TSAA, 3.75% calcium and 0.70% phosphorus.

                                      TABLE H                                     __________________________________________________________________________                   Experiment Diets for Zeolite Study (Weight Percent)                           Diet No.                                                                      9   10  11  12     13  14  15  16                                             0.51% TSAA         0.61% TSAA                                  Ingredient Name                                                                              0.00%                                                                             0.75%                                                                             1.50%                                                                             0.68 (special)                                                                       0.00%                                                                             0.75%                                                                             1.50%                                                                             0.68 (special)                  __________________________________________________________________________    Corn           67.65                                                                             67.65                                                                             67.65                                                                             67.65  62.07                                                                             62.07                                                                             62.07                                                                             62.07                           SBM (48%)      18.19                                                                             18.19                                                                             18.19                                                                             18.19  23.81                                                                             23.81                                                                             23.81                                                                             23.81                           Alfalfa (17%)  1.00                                                                              1.00                                                                              1.00                                                                              1.00   1.00                                                                              1.00                                                                              1.00                                                                              1.00                            Dicalcium Phosphate (18.5%)                                                                  2.12                                                                              2.12                                                                              2.12                                                                              2.12   2.01                                                                              2.01                                                                              2.01                                                                              2.01                            Limestone      8.47                                                                              8.47                                                                              8.47                                                                              8.29   8.50                                                                              8.50                                                                              8.50                                                                              8.31                            DL-methionine  --  --  --  --     0.04                                                                              0.04                                                                              0.04                                                                              0.04                            Salt           0.35                                                                              0.10                                                                              --  0.35   0.35                                                                              0.10                                                                              --  0.35                            Micro-mix      0.50                                                                              0.50                                                                              0.50                                                                              0.50   0.50                                                                              0.50                                                                              0.50                                                                              0.50                            Sand           1.72                                                                              0.82                                                                              --  1.22   1.72                                                                              0.82                                                                              --  1.23                            Zeolite        --  0.75                                                                              1.50                                                                              0.68   --  0.75                                                                              1.50                                                                              0.68                            HCl             -- 0.40                                                                              0.57                                                                              --     --  0.40                                                                              0.57                                                                              --                              TOTAL          100.0                                                                             100.0                                                                             100.0                                                                             100.0  100.0                                                                             100.0                                                                             100.0                                                                             100.0                           __________________________________________________________________________

The results of the tests are summarized in Tables P, J, K, L, M, and N.

                                      TABLE P                                     __________________________________________________________________________    EGG SPECIFIC GRAVITY*                                                              No. of                                      Avg. for                     Diet Eggs                                                                              Week 0                                                                             Week 1                                                                             Week 2                                                                             Week 3                                                                             Week 4                                                                             Week 6                                                                             Week 7                                                                             Week 8                                                                             8 Weeks                      __________________________________________________________________________     9-12                                                                              240 89.24                                                                              90.54                                                                              88.87                                                                              88.53                                                                              90.05                                                                              87.80                                                                              88.47                                                                              87.18                                                                              88.34                        13-16                                                                              240 89.86                                                                              91.24                                                                              88.84                                                                              89.30                                                                              90.19                                                                              88.38                                                                              88.06                                                                              87.87                                                                              89.22                         9 and 13                                                                          120 89.34                                                                              89.93                                                                              87.90                                                                              87.94                                                                              88.88                                                                              86.81                                                                              87.67                                                                              86.66                                                                              88.14                        10 and 14                                                                          120 89.38                                                                              90.85                                                                              89.01                                                                              88.60                                                                              89.93                                                                              88.25                                                                              88.43                                                                              87.03                                                                              88.94                        11 and 15                                                                          120 90.44                                                                              92.07                                                                              90.13                                                                              90.01                                                                              91.29                                                                              89.40                                                                              88.88                                                                              88.57                                                                              90.10                        12 and 16                                                                          120 89.06                                                                              90.71                                                                              88.40                                                                              89.11                                                                              90.40                                                                              87.89                                                                              88.06                                                                              87.84                                                                              88.93                         9   60  89.27                                                                              89.25                                                                              87.83                                                                              87.46                                                                              88.36                                                                              86.14                                                                              88.09                                                                              86.49                                                                              87.86                        10   60  89.16                                                                              90.89                                                                              89.76                                                                              87.78                                                                              90.48                                                                              88.08                                                                              88.68                                                                              86.40                                                                              88.90                        11   60  90.04                                                                              91.73                                                                              89.92                                                                              90.00                                                                              91.23                                                                              89.27                                                                              89.07                                                                              88.07                                                                              88.92                        12   60  88.50                                                                              90.31                                                                              87.99                                                                              88.89                                                                              90.16                                                                              87.71                                                                              88.04                                                                              87.78                                                                              88.67                        13   60  89.41                                                                              90.61                                                                              87.97                                                                              88.43                                                                              89.39                                                                              87.48                                                                              87.24                                                                              86.83                                                                              88.42                        14   60  89.60                                                                              90.81                                                                              88.27                                                                              89.41                                                                              89.39                                                                              88.41                                                                              88.21                                                                              87.66                                                                              88.97                        15   60  90.83                                                                              92.41                                                                              90.33                                                                              90.02                                                                              91.35                                                                              89.53                                                                              88.69                                                                              89.07                                                                              90.28                        16   60  89.62                                                                              92.12                                                                              88.80                                                                              89.33                                                                              90.64                                                                              88.08                                                                              88.09                                                                              87.91                                                                              89.20                        __________________________________________________________________________     *Divide by 1000 and add 1 to convert to Actual Specific Gravity.         

                                      TABLE J                                     __________________________________________________________________________    EGG PRODUCTION (Percent Hen Per Day)                                          No. of                                        Avg.                            Percent                                       for                             Calcula-  Week No.                            12                              Diet tions                                                                              1  2  3  4  5  6  7  8  9  10 11 12 Weeks                           __________________________________________________________________________     9-12                                                                              240  57.26                                                                            69.54                                                                            78.04                                                                            80.82                                                                            84.93                                                                            87.00                                                                            85.83                                                                            89.24                                                                            88.33                                                                            87.81                                                                            81.55                                                                            87.87                                                                            81.52                           13-16                                                                              240  53.41                                                                            69.40                                                                            81.83                                                                            87.13                                                                            89.39                                                                            89.92                                                                            89.18                                                                            89.92                                                                            87.53                                                                            88.76                                                                            84.13                                                                            88.24                                                                            83.24                            9 and 13                                                                          120  53.73                                                                            71.31                                                                            82.12                                                                            85.19                                                                            87.94                                                                            87.86                                                                            86.34                                                                            89.48                                                                            89.22                                                                            87.63                                                                            82.06                                                                            85.29                                                                            82.35                           10 and 14                                                                          120  60.23                                                                            71.31                                                                            75.71                                                                            76.47                                                                            82.74                                                                            89.22                                                                            89.52                                                                            91.19                                                                            88.69                                                                            90.12                                                                            86.19                                                                            90.60                                                                            82.58                           11 and 15                                                                          120  51.93                                                                            64.32                                                                            78.01                                                                            85.01                                                                            87.65                                                                            89.17                                                                            85.76                                                                            88.61                                                                            86.73                                                                            88.86                                                                            83.31                                                                            87.59                                                                            81.41                           12 and 16                                                                          120  55.43                                                                            70.95                                                                            83.89                                                                            89.25                                                                            90.31                                                                            88.60                                                                            88.40                                                                            89.04                                                                            87.06                                                                            86.52                                                                            79.79                                                                            88.74                                                                            83.16                            9   60   55.00                                                                            70.48                                                                            80.24                                                                            81.67                                                                            85.48                                                                            87.14                                                                            82.86                                                                            88.34                                                                            88.81                                                                            87.14                                                                            77.82                                                                            84.76                                                                            80.79                           10   60   60.95                                                                            70.95                                                                            70.48                                                                            67.86                                                                            76.43                                                                            85.24                                                                            88.34                                                                            91.43                                                                            89.76                                                                            89.29                                                                            85.48                                                                            89.76                                                                            80.50                           11   60   56.72                                                                            70.08                                                                            81.75                                                                            87.88                                                                            88.15                                                                            88.18                                                                            83.41                                                                            87.94                                                                            87.04                                                                            88.92                                                                            83.28                                                                            89.57                                                                            82.57                           12   60   56.35                                                                            66.67                                                                            79.68                                                                            85.87                                                                            89.66                                                                            87.43                                                                            88.71                                                                            89.26                                                                            87.70                                                                            85.90                                                                            79.81                                                                            89.39                                                                            82.20                           13   60   52.46                                                                            72.14                                                                            83.99                                                                            88.71                                                                            90.40                                                                            88.57                                                                            89.82                                                                            90.63                                                                            89.63                                                                            88.12                                                                            86.51                                                                            85.82                                                                            83.90                           14   60   59.53                                                                            71.67                                                                            80.95                                                                            85.07                                                                            89.05                                                                            91.19                                                                            90.71                                                                            90.95                                                                            87.62                                                                            90.95                                                                            86.91                                                                            91.43                                                                            84.67                           15   60   47.14                                                                            58.57                                                                            74.28                                                                            82.14                                                                            87.14                                                                            90.17                                                                            88.10                                                                            89.29                                                                            86.43                                                                            88.81                                                                            83.33                                                                            87.62                                                                            80.25                           16   60   54.52                                                                            75.24                                                                            88.10                                                                            92.62                                                                            90.95                                                                            89.76                                                                            88.10                                                                            88.81                                                                            86.43                                                                            87.15                                                                            79.76                                                                            88.10                                                                            84.13                           __________________________________________________________________________

                  TABLE K                                                         ______________________________________                                        SHELL WEIGHT (Grams/Egg)                                                                No. of                    Avg. for                                  Diet      Eggs    Week 1     Week 2 2 Weeks                                   ______________________________________                                         9-12     240     5.58       5.54   5.56                                      13-16     240     5.67       5.63   5.65                                       9 and 13 120     5.52       5.60   5.56                                      10 and 14 120     5.59       5.55   5.57                                      11 and 15 120     5.68       5.60   5.64                                      12 and 16 120     5.70       5.59   5.65                                       9        60      5.45       5.54   5.49                                      10        60      5.60       5.54   5.57                                      11        60      5.63       5.53   5.58                                      12        60      5.64       5.54   5.59                                      13        60      5.60       5.65   5.62                                      14        60      5.59       5.56   5.57                                      15        60      5.73       5.64   5.70                                      16        60      5.76       5.64   5.70                                      ______________________________________                                    

                                      TABLE L                                     __________________________________________________________________________    FEED CONSUMPTION (Grams Per Hen Per Day)                                           No. of                                                                        Weigh-   Week                                                                              Week                                                                              Week                                                                              Week                                                                              Week                                                                              Week                                                                              Week                                                                              Week                                                                              Week                                                                              Week                                                                              Week                    Diet ings                                                                              Week 1                                                                             2   3   4   5   6   7   8   9   10  11  12  12                  __________________________________________________________________________                                                              Weeks                9-12                                                                              240 48.46                                                                              99.99                                                                             109.73                                                                            119.50                                                                            122.02                                                                            124.81                                                                            121.58                                                                            120.55                                                                            119.90                                                                            116.19                                                                            127.07                                                                            126.87                                                                            113.06              13-16                                                                              240 46.83                                                                              99.44                                                                             108.18                                                                            115.65                                                                            117.85                                                                            120.77                                                                            118.26                                                                            118.37                                                                            118.88                                                                            115.16                                                                            123.32                                                                            127.25                                                                            110.89               9 and 13                                                                          120 50.38                                                                              102.66                                                                            111.29                                                                            119.56                                                                            122.97                                                                            122.55                                                                            121.86                                                                            120.09                                                                            119.88                                                                            114.09                                                                            126.58                                                                            127.97                                                                            113.41              10 and 14                                                                          120 51.39                                                                              97.54                                                                             106.64                                                                            115.63                                                                            121.17                                                                            123.85                                                                            120.33                                                                            120.67                                                                            120.22                                                                            117.38                                                                            127.20                                                                            128.18                                                                            112.52              11 and 15                                                                          120 40.78                                                                              95.91                                                                             106.74                                                                            116.19                                                                            116.49                                                                            120.14                                                                            115.64                                                                            115.23                                                                            115.71                                                                            112.91                                                                            123.17                                                                            123.68                                                                            108.55              12 and 16                                                                          120 48.02                                                                              102.77                                                                            111.14                                                                            118.91                                                                            119.03                                                                            124.61                                                                            121.86                                                                            121.83                                                                            121.32                                                                            117.33                                                                            125.82                                                                            128.41                                                                            113.42               9   60  55.36                                                                              107.40                                                                            116.61                                                                            123.85                                                                            126.99                                                                            124.25                                                                            126.59                                                                            124.45                                                                            121.78                                                                            115.12                                                                            127.93                                                                            129.53                                                                            116.66              10   60  50.04                                                                              94.97                                                                             102.57                                                                            115.92                                                                            121.49                                                                            126.62                                                                            122.74                                                                            123.44                                                                            122.81                                                                            118.76                                                                            130.94                                                                            129.54                                                                            113.32              11   60  41.59                                                                              96.84                                                                             109.08                                                                            117.39                                                                            116.79                                                                            120.14                                                                            225.64                                                                            113.21                                                                            115.28                                                                            111.69                                                                            123.85                                                                            121.46                                                                            108.58              12   60  46.84                                                                              100.76                                                                            110.66                                                                            120.83                                                                            122.83                                                                            128.23                                                                            121.34                                                                            121.08                                                                            119.75                                                                            119.21                                                                            125.55                                                                            126.94                                                                            113.67              13   60  45.40                                                                              97.91                                                                             105.97                                                                            115.27                                                                            118.95                                                                            120.85                                                                            117.12                                                                            115.74                                                                            117.97                                                                            115.06                                                                            125.23                                                                            126.42                                                                            110.16              14   60  52.74                                                                              100.10                                                                            110.72                                                                            115.33                                                                            121.04                                                                            121.08                                                                            117.92                                                                            117.90                                                                            117.63                                                                            115.99                                                                            123.47                                                                            126.82                                                                            111.73              15   60  40.00                                                                              94.98                                                                             104.39                                                                            115.00                                                                            116.20                                                                            120.14                                                                            115.63                                                                            117.25                                                                            116.14                                                                            114.14                                                                            122.50                                                                            125.90                                                                            108.52              16   60  49.20                                                                              104.78                                                                            111.62                                                                            116.99                                                                            115.22                                                                            121.00                                                                            122.39                                                                            122.58                                                                            122.90                                                                            115.46                                                                            126.08                                                                            129.88                                                                            113.17              __________________________________________________________________________

                  TABLE M                                                         ______________________________________                                        BODY WEIGHT (Grams per Hen)                                                                 No. of                                                          Diet No.      Weighings Difference                                            ______________________________________                                         9-12         240       218.00                                                13-16         240       219.46                                                 9 and 13     120       228.25                                                10 and 14     120       219.50                                                11 and 15     120       205.33                                                12 and 16     120       221.83                                                 9            60        239.50                                                10            60        228.33                                                11            60        179.67                                                12            60        224.50                                                13            60        217.00                                                14            60        210.67                                                15            60        231.00                                                16            60        219.17                                                ______________________________________                                    

                                      TABLE N                                     __________________________________________________________________________    EGG WEIGHTS (Grams per Egg)                                                        No. of                                        Avg. for                   Diet Weighings                                                                           1 Week                                                                             2 Weeks                                                                            3 Weeks                                                                            4 Weeks                                                                            6 Weeks                                                                            8 Weeks                                                                            10 Weeks                                                                           12 Weeks                                                                           12 Weeks                   __________________________________________________________________________     9-12                                                                              240   51.42                                                                              51.86                                                                              53.42                                                                              54.07                                                                              55.48                                                                              56.49                                                                              57.57                                                                              58.72                                                                              58.88                      13-16                                                                              240   52.57                                                                              53.90                                                                              55.04                                                                              55.94                                                                              57.21                                                                              57.88                                                                              58.79                                                                              59.82                                                                              56.39                       9 and 13                                                                          120   52.05                                                                              53.10                                                                              54.82                                                                              55.18                                                                              56.38                                                                              57.19                                                                              58.35                                                                              59.30                                                                              55.80                      10 and 14                                                                          120   52.24                                                                              52.38                                                                              53.18                                                                              54.36                                                                              56.24                                                                              57.29                                                                              58.37                                                                              59.29                                                                              55.42                      11 and 15                                                                          120   51.28                                                                              52.31                                                                              54.13                                                                              55.04                                                                              56.18                                                                              56.87                                                                              57.53                                                                              59.00                                                                              55.29                      12 and 16                                                                          120   52.43                                                                              53.73                                                                              54.78                                                                              55.45                                                                              56.59                                                                              57.39                                                                              58.48                                                                              59.48                                                                              56.03                       9   60    51.30                                                                              52.08                                                                              54.25                                                                              54.49                                                                              55.39                                                                              56.71                                                                              57.71                                                                              59.08                                                                              55.11                      10   60    51.72                                                                              51.05                                                                              52.06                                                                              53.10                                                                              55.54                                                                              57.00                                                                              58.01                                                                              59.20                                                                              54.79                      11   60    51.31                                                                              51.81                                                                              53.95                                                                              54.35                                                                              55.38                                                                              56.09                                                                              56.65                                                                              58.38                                                                              54.74                      12   60    51.36                                                                              52.50                                                                              53.51                                                                              54.36                                                                              55.62                                                                              56.18                                                                              57.91                                                                              58.21                                                                              54.96                      13   60    52.79                                                                              54.11                                                                              55.49                                                                              55.87                                                                              57.37                                                                              57.68                                                                              58.99                                                                              59.53                                                                              56.48                      14   60    52.76                                                                              53.71                                                                              54.30                                                                              55.62                                                                              56.93                                                                              57.58                                                                              58.74                                                                              59.37                                                                              56.13                      15   60    51.25                                                                              52.82                                                                              54.32                                                                              55.74                                                                              56.98                                                                              57.64                                                                              58.41                                                                              59.62                                                                              55.85                      16   60    53.51                                                                              54.96                                                                              56.05                                                                              56.53                                                                               57.566                                                                            58.60                                                                              59.04                                                                              60.75                                                                              57.12                      __________________________________________________________________________

A review of the test data in Tables P and J through N shows thatsubstantially the same results were obtained as those in Tables Bthrough H.

In a preliminary study of a relatively few laying hens with one percentzeolite in the diet it was indicated that the relative ranks of zeolitesin improving shell strength were as follows:

    ______________________________________                                        Rank            Shell Strength                                                ______________________________________                                        1               Zeolite A                                                     2               Synthetic Mordenites                                          3               Synthetic Zeolite X                                           4               Natural Erionite                                              5               Natural Clinoptilolite                                        6               Synthetic Zeolite Y                                           ______________________________________                                    

In shell strength, the controls were inferior to or equal to the poorestof all the zeolites.

The later studies clearly show that zeolite A is effective in increasingshell strength. Some increase in shell strength using mordenite shouldalso be expected.

The term poultry includes all domestic fowl, namely chickens, turkeys,ducks, geese, and the like.

Corn is the principal diet for most laying poultry. A feed formulationcomprising by weight percent the following is desirable:

    ______________________________________                                                      Weight Percent                                                  ______________________________________                                        corn            50-75                                                         soybean meal    10-30                                                         calcium carbonate                                                                              4-10                                                         zeolite A       0.25-4.0                                                      ______________________________________                                    

Calcium carbonate is usually in the form of natural limestone ground toa suitable particle size, but sometimes oyster shells which have alsobeen suitably ground are used.

It can be appreciated that a wide variety of nutrients or foods may beincluded in the diets of layers or poultry laying hens. In a controlledenvironment, the hens are only exposed to desired foods or foodproducts. A typical laying ration composition contains the following:

    ______________________________________                                                           Weight Percent                                             ______________________________________                                        crude protein not less than                                                                            16.0                                                 crude fat     not less than                                                                            2.5                                                  crude fiber   not more than                                                                            7.0                                                  calcium (as Ca)                                                                             not less than                                                                            3.1                                                  calcium (as Ca)                                                                             not more than                                                                            4.1                                                  phosphorus (P)                                                                              not less than                                                                            0.5                                                  iodine (I)    not less than                                                                              0.0001                                             salt (NaCl)   not less than                                                                            0.3                                                  salt (NaCl)   not more than                                                                            0.9                                                  ______________________________________                                    

The foregoing composition is obtained from or included the followingingredients:

Grain and processed grain by-products. Includes corn, corn hominy, corngerm meal, barley, millet, oats, rice, rice hulls, rye, sorghum, wheatand wheat shorts. These are among the energy ingredients, mostlycarbohydrates with some proteins.

Plant protein products. Includes soybean oil meal, barley malt sprouts,coconut meal, corn distillers grain, corn gluten meal, cottonseed meal,pea seed, potato meal, peanut meal, rape seed meal, sunflower meal,wheat germ meal, brewers' yeast. All of these are protein sources.

Roughage or fiber. Includes dehydrated alfalfa, alfalfa hay, alfalfaleaf meal and pasture grasses. These are all fiber sources.

Animal and fish by-products. Includes blood meal, blood flour, driedbuttermilk, dried whey, dried casein, fish meal, dried fish solubles,liver meal, meat meal, meat meal tankage, bone meal and dried skim milk.Anchovies, herring and menhaden are sources of fish meal.

Minerals and synthetic trace ingredients. Includes vitamins such asB-12, A, pantothenate, niacin, riboflavin, K, etc., DL methionine,choline chloride, folic acid, dicalcium phosphate, magnesium sulfonate,potassium sulfate, calcium carbonate (limestone, oyster shells), salt,sodium selenite, manganous oxide, calcium iodate, copper oxide, zincoxide and D activated animal sterol.

Molasses and animal fats are added to improve palatability and toincrease or balance the energy levels.

Preservatives are also added such as, Ethoxyquin™ and sodium sulfite.

In general, a feed composition for poultry laying hens should preferablycontain by weight percent the following:

    ______________________________________                                                            Weight Percent                                            ______________________________________                                        crude protein                                                                             at least about                                                                              14                                                  crude fat   at least about                                                                              2                                                   crude fiber not more than about                                                                         7                                                   calcium     about         2.7 to 4.1                                          phosphorous at least about                                                                              0.05                                                iodine      at least      0.0001                                              sodium      about         0.1 to 0.4                                          chlorine    about         0.1 to 0.5                                          zeolite A   about         0.25 to 4.0                                         ______________________________________                                    

The foregoing disclosure and description of the invention isillustrative and explanatory thereof and various changes in theillustrated process may be made within the scope of the appended claimswithout departing from the spirit of the invention.

What is claimed is:
 1. A method of increasing the quality of the eggshell of a poultry laying hen wherein an effective amount of zeolite Asufficient to improve the quality of the egg shell up to about 4 weightpercent of the feed is added to the feed of the hen and the feed is fedto the hen.
 2. The method of claim 1, wherein the amount of zeolite Aadded to the feed is from about 0.25 percent to three percent by weight.3. The method of claim 1, wherein the amount of zeolite A added to thefeed is about 0.75 weight percent.
 4. The method of claim 1, wherein theamount of zeolite A added to the feed is about 1.5 weight percent.
 5. Amethod of increasing the quality of the egg shell of the eggs of layingpoultry wherein a feed formulation comprising principally corn, andabout 0.25 to about 4.00 percent by weight of zeolite A is fed to thelaying poultry.
 6. The method of claim 5, wherein the feed formulationcontains zeolite A in an amount of about 0.75 to about 1.5 weightpercent.
 7. A method of increasing the quality of the egg shell oflaying poultry, wherein a feed formulation comprising by weight percent,50-75 percent corn, 10-30 percent soybean meal and 4-10 percent calciumcarbonate, and about 0.25 percent to about 4.0 percent by weight ofzeolite A is fed to the laying poultry.
 8. The method of claim 7,wherein the feed formulation contains zeolite A in an amount of about0.75 to about 1.5 weight percent.
 9. A method of increasing the qualityof the egg shell of poultry laying hens, wherein said hens are fed afeed composition comprising proteins, carbohydrates, minerals andvitamins and about 0.25 percent to about 4.0 percent by weight ofzeolite A.
 10. The method of claim 9, wherein said zeolite A in saidfeed composition is in an amount of about 0.75 to about 1.5 weightpercent.
 11. A method of increasing the quality of the egg shell of theeggs of poultry laying hens wherein a feed composition comprising byweight percent the following:crude protein: at least 14 crude fat: atleast 2 crude fiber: not more than 7.0 calcium: about 2.7 to 4.1phosphorus: at least 0.4 iodine: at least 0.0001 sodium: about 0.1 to0.4 chloride: about 0.1 to 0.5 zeolite A: about 0.25 to 4.0is fed to thepoultry laying hens.
 12. A method of increasing the quality of the eggshell of the eggs of poultry laying hens wherein a feed compositioncomprising by weight percent the following:crude protein: at least 16crude fat: at least 2.5 crude fiber: mot more than 7.0 calcium: about3.1 to 4.1 phosphorus: at least 0.5 iodine: at least 0.0001 sodium:about 0.1 to 0.3 chloride: about 0.1 to 0.3 zeolite A: about 0.25 to4.0is fed to the poultry laying hens.